You can watch TV shows online for free on several legal platforms without needing to pay or provide credit card details. Popular options include:

• SeriesOnline: Offers free streaming of series and movies in HD quality without requiring registration or payment.

• Plex: Provides over 20,000 free movies and TV shows, including live TV, accessible on many devices.

• Popcornflix: A free streaming website with a variety of TV shows and movies, no registration required.

• YouTube: Has an extensive library of free, ad-supported movies and TV shows legally available.

• Tubi, Pluto TV, and Freevee: These ad-supported platforms host a large catalog of free series for streaming with minimal interruptions and no subscription.

These services usually show ads like traditional TV but enable free access to quality content across many genres and devices. They are excellent options to watch TV shows online for free safely and legally.